> ## Documentation Index
> Fetch the complete documentation index at: https://docs.apostra.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Practice buyer briefs and compare responses

> Use a practice brief or the Merchandising Simulator to see how your agent would answer a buyer request before it is live.

Use a **practice brief** when you want to see how your agent would answer a
buyer request. Paste the brief into your assistant and ask it to practise
answering the brief. This creates a practice result for you to review. It does
not contact a buyer, create a media buy, or change your live storefront.

Use the **Merchandising Simulator** when you want to compare answers to the
same brief. Ask your assistant to create a simulation from a brief. The
Simulator runs your current configuration alongside the changes you declare,
then shows the results side by side. A simulation does not change your live
configuration.

## Choose the right rehearsal

Choose a practice brief when you want one answer to a buyer brief and want to
review that answer with your team. Choose the Simulator when you want to see
how a proposed change, such as a different selling posture or product choice,
would affect the answer to the same brief.

If you paste a buyer brief, your assistant can help you choose either option.
It should not treat the brief as a request to set up an advertiser or start a
buyer campaign.

## Start from a brief

You can use a brief you wrote for rehearsal or a buyer brief you received. For
the most useful result, include the request's goal, channels or formats,
markets, timing, and budget when you have them. The practice result and the
Simulator show what your agent can support from your current storefront. They
do not predict whether a buyer will accept or book the offer.

## Availability

Practice and Simulator access can be enabled for your storefront. If your
assistant cannot open either option, ask an account administrator whether your
storefront has access.

If you are ready to handle a real buyer request rather than rehearse one, use
the [Seller RFP lifecycle](/v3/rfp-lifecycle) instead.


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